This invention concerns shrimp trawls in general and more particularly a beam or frame type shrimp trawl having a transverse, forward beam which is centrally hinged and a towline and bridle arrangement to open and close the trawl from the vessel towing the shrimp trawl.
In commercial shrimp fishing, there are two categories of trawl net structures used, these being beam trawls wherein the mouth of the trawl net is kept open by a transverse beam, and otter trawls wherein the mouth of the trawl is kept open by the force of water against otter boards or doors at each side of the mouth of the trawl as the trawl is towed across the sea floor.
Otter trawls have the particular advantage of being easily stored in a compact area aboard the ship or vessel when the trawl is not in use. However, fishing with an otter trawl can be rather complicated as vessel speed must be matched with otter board configuration and design to assure the trawl remains open during use.
Conversely, the beam trawl is far more easily used, as the transverse beam at the mouth of the trawl keeps it open during towing. The major drawback of beam trawls is that the beam is rather unwieldly to handle on deck; the trawl takes up considerable space when stored. Also, lowering of a beam trawl into water and its removal onto the deck of the vessel after fishing can be a tricky, cumbersome process.
A wheeled beam trawl having a fixed, non-folding central beam is disclosed in U.S. Pat. No. 3,458,947 issued Aug. 5, 1969 to John J. Ross. A similarly structured sponge trawl is disclosed in U.S. Pat No. Re. 10,688 issued Feb. 16, 1886 to Basilios K. Moscopoulos and is provided with detachable end members to facilitate breakdown and storage of the trawl when not in use. A beam trawl having a centrally hinged beam so the trawl may be more easily stowed aboard ship is disclosed in U.S. Pat. No. 3,775,891 issued Dec. 4, 1973 to John K. Holt. However, the beam trawl disclosed therein is folded in the direction of tow rather than towards the trailing trawl and no provision is made to open and close the trawl while it is still in the water. Additionally, this trawl is not wheeled, but instead provided with sled runners, and a relatively bulky framework for defining the forward, open end of the trawl. U.S. Pat. No. 953,069 issued Mar. 29, 1910 to Hiram H. Thompson discloses a somewhat related structure in the form of a fish trawl havng a frame structure defining the open, forward end of the net, the frame being an inverted, hinged U-shaped assembly so the net may be folded for storage.
Stabilizing wings or similar structures are disclosed in U.S. Pat. No. 2,729,910 issued Jan. 10, 1956 to Robert A. Fryklund; U.S. Pat. No. Re. 25,165 issued May 1, 1962 to Orville B. Pulsifer; and U.S. Pat No. 4,082,055 issued Apr. 4, 1978 to Daniel M. Brown.
What is not disclosed by the prior art is a collapsible, wheel supported shrimp trawl which is centrally hinged and capable of being folded and unfolded from the shrimp boat while the trawl is still in the water to thus facilitate loading of the trawl onto the boat after use and unfolding of the trawl in water for a fishing operation, the trawl further having stabilizing wings for keeping the trawl on the sea floor when in use and a separate set of wheels for supporting the forward end of the net lead line.